Brooks, Bryan W.Fulton, Barry A.Baylor University. Dept. of Environmental Science.2009-07-012009-07-012009-052009-07-01http://hdl.handle.net/2104/5351Includes bibliographical references (p. 65-72).In the present study, influences of nutrient availability on triclosan toxicity to a model aquatic macrophyte Lemna gibba were explored. Triclosan effective concentrations varied by up to 6.5-fold depending on nutrient treatment and standardized endpoint. Mesocosm results validated these laboratory findings by also indicating greater triclosan-inhibition under higher P-availability. Ecologically relevant endpoints such as elemental stoichiometry and uptake were also differentially affected according to nutrient – triclosan treatments. In particular, tissue-N inhibition was more pronounced that tissue-P leading to N:P dose-response trends, which were most sensitive in P-limited exposure media. These stoichiometric endpoints were generally less sensitive compared to standardized growth endpoints, except under a P-limited scenario. Interactions between nutrients and contaminants were further highlighted by variable triclosan toxicity to N-uptake kinetics determined over an N-gradient. Significant inhibition to N-uptake kinetics was determined for plants co-exposed at high N concentrations while lower N-availability did not result in significant N-uptake inhibition.xi, 72 p. : ill.143641 bytes855999 bytesapplication/pdfapplication/pdfen-USBaylor University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact librarywebmaster@baylor.edu for inquiries about permission.Nutrient interactions -- Analysis.Pollution -- Environmental aspects.Aquatic plants -- Effect of water pollution on.Water -- Pollution -- Toxicology.Spoichiometry.ThesisBaylor University access only